Clinical Trials

Oklahomans diagnosed with cancer don’t have to pay for expensive, out-of-state travel or experience the anxiety of separation from family and friends in order to receive the most up-to-date treatments in cancer therapy. OCSRI participates in clinical trials to provide Oklahomans with the latest developments in cancer research.

“Almost all of the clinical advances in oncology have come about because of trials, ” says Dr. Daron Street, OCSRI Chairman of the Board. “There are so many exciting treatments on the horizon thanks to clinical trials. Not only do clinical trials improve survival rates, they also contribute to lower cancer recurrence rates, new treatment approaches for cancers that have no effective therapy, fewer side effects and a better quality of life. With clinical trials, patients have access to some of the newest and most effective drugs and treatments which are otherwise not available to them.”

For more information about clinical trials, visit the National Cancer Institute.

What is a Clinical Trial?

Clinical trials are research studies that involve people. They are the final step in a long process that begins with research in a lab. Most treatments we use today are the results of past clinical trials.

Cancer clinical trials are designed to test new ways to:

  • Treat cancer
  • Find and diagnose cancer
  • Prevent cancer
  • Manage symptoms of cancer or side effects from its treatment

Any time you or a loved one needs treatment for cancer, clinical trials are an option to think about. Trials are available for all stages of cancer. It is a myth that they are only for people who have advanced cancer that is not responding to treatment.

Every trial has a person in charge, usually a doctor, who is called the principal investigator. The principal investigator prepares a plan for the trial, called a protocol. The protocol explains what will be done during the trial. It also contains information that helps the doctor decide if this treatment is right for you. The protocol includes information about:

  • The reason for doing the trial
  • Who can join the trial (called “eligibility requirements”)
  • How many people are needed for the trial
  • Any drugs that will be given, how they will be given, the dose, and how often
  • What medical tests will be done and how often
  • What types of information will be collected about the people taking part

Phases of Clinical Trials

Clinical trials to test new cancer treatments involve a series of steps, called phases. If a new treatment is successful in one phase, it will proceed to further testing in the next phase. During the early phases (phases 1 and 2), researchers figure out whether a new treatment is safe, what its side effects are, and the best dose of the new treatment. They also make sure that the treatment has some benefit, such as slowing tumor growth. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid.

There are also very early (phase 0) and later (phase 4) phase clinical trials. These trials are less common. Phase 0 trials are very small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness. They take place after a new treatment has been approved and is on the market.

The following shows the number of patients that take part and the purpose of the most common phases. Although the trial phases are explained in the context of drug treatment trials, the same concepts apply to most types of clinical trials.

Phase 1


  • To find a safe dose
  • To decide how the new treatment should be given (by mouth, in a vein, etc.)
  • To see how the new treatment affects the human body

Number of people taking part: 15–30

Phase 2


  • To determine if the new treatment has an effect on a certain cancer
  • To see how the new treatment affects the body

Number of people taking part: Less than 100

Phase 3


To compare the new treatment (or new use of a treatment) with the current standard treatment

Number of people taking part: From 100 to several thousand

Some researchers design trials that combine two phases (phase 1/2 or phase 2/3 trials) in a single protocol. In this combined design, there is a seamless transition between trial phases, which may allow research questions to be answered more quickly or with fewer patients.